Crypto unit converters

Crypto denominations sit on top of each other in powers of 10: 1 ETH = 10⁹ Gwei = 10¹⁸ Wei; 1 BTC = 10⁸ Satoshi. Trivial arithmetic until you try to do it with JavaScript’s double-precision floats, which silently lose precision past 15-17 digits. The tools below use BigInt throughout so the math is exact at any scale.